[clang-tools-extra] [clang-tidy] Speed up/rewrite `bugprone-stringview-nullptr` (PR #192889)

[Daniil Dudkin via cfe-commits]

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@@ -19,21 +19,13 @@ namespace clang::tidy::bugprone {
 /// braced initializer list does not compile so instead a call to `.empty()` or
 /// the empty string literal are used, where appropriate.
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unterumarmung wrote:

And I guess this should be updated...

https://github.com/llvm/llvm-project/pull/192889